The present invention relates to a lining material and more particularly, but not exclusively, to a lining material for footwear.
A large number of products include a lining material for a variety of reasons. For example, a lining material is used within footwear to improve wearer comfort, abrasion resistance and for presentational reasons. Alternatively, linings are applied to clothing and other products in order to achieve a similar wear abrasion, moisture control and simply to facilitate more efficient product construction or operation.
Of particular concern with some lining materials is the ability to wick away moisture from damp areas and this is a particular requirement in footwear linings. Absorbent fibres can be used in linings to facilitate this moisture wick ability. However, the abrasion resistance of linings using such fibres has been limited. More recently, improved wicking synthetic fibres have been developed which have a grooved cross-section to promote capillary transport of moisture along the fibre and thus disperse moisture more rapidly about the lining material made from such fibres.
One type of lining material is a non-woven felt comprising appropriately needle entangled fibres to form a felt of suitable weight and gauge for the product in which the lining is to be applied. One such lining is marketed by British United Shoe Machinery Limited, Leicester, England under the trademark Aquiline. In order to incorporate such grooved cross section fibres for their wicking efficiency within a non-woven fabric, the grooved cross-section fibres it will generally be needle entangled as with previous felts. However, it has been found with typically available grooved cross section fibres, such as fibre 4DG supplied by the Eastman Chemical Company of Tennessee, USA or multi-lobed cross-section such as fibres-sold as Dacron, in simple fibre entangled felts have had too high an abrasion rate for acceptable performance in such products as footwear or clothing. Furthermore, the felts have had too high a stretch rate during product manufacture.
It will be appreciated that generally non-woven felts depend upon fibre entanglement and fibre friction slip resistance to ensure consolidation. Thus, with grooved or multi-lobed cross section fibres it may be that there is less surface contact between fibres to provide such entanglement and friction resistance i.e. only the tops of the grooves or channels are available as compared to a generally round cross section fibre. The valleys of the channels are not available even though they do provide the facility of capillary wicking as indicated above and are available for application of a suitable coating for hydrophobic or hydrophobic attraction of moisture or other desired performance criteria e.g. electrical/thermal conductivity, ph resistance etc. With regard to stretching, it will be appreciated that the felt may become distorted after a manufacturing stage due to fibre slippage passed one another and there will be no xe2x80x98bounce backxe2x80x99 to its original shape.
It is an object of the present invention to provide a lining material based upon non-woven felts that incorporates grooved or multi-lobed cross sectioned fibres for improved wicking whilst maintaining acceptable abrasion levels and properties adequate for shoe manufacture and for durability in use.
In accordance with the present invention there is provided a lining material for footwear, the material comprising a non-woven felt made of up to 80% by weight of grooved or multi-lobed cross section transport fibres and the remainder thermally bondable fibres arranged to secure said transport fibres against abrasion and excessive mechanical stretch present during incorporation of such lining material into a product during that product""s manufacture.
Preferably the transport fibres are 4DG fibre supplied by the Eastman Chemical Company of Tennessee, USA or Dacron.
Preferably the thermally bondable fibres may be polypropylene fibres, bicomponent fibres or low melting polyester fibres, all of the appropriate decitex.
In replacement of a certain proportion of the transport fibres, anti-bacterial fibres or other special performance fibres may be included in the non woven felt.
Preferably, the lining material has a density in the range 150-160 kg per cubic meter and preferably about 156 kg per cubic meter. The material preferably has a weight of 250 gsm and a gauge of 1.6 mm but may have a weight in the range 100-400 gsm.
Preferably the thermally bondable fibres have a decitex in the range 1.7-5.0 decitex but in any event sufficient to allow upon heating the transport fibres to be resiliently bonded or embedded within the thermally bondable fibres without the thermally bondable fibres melting completely. The preferred decitex of the thermally bondable fibres is 2.5 whilst the transport fibres may have a decitex in the range 2.5 to 4.0 decitex but most advantageously, with 4DG fibre, of 3.3 decitex.
The preferred composition of the lining material is 70% 4DG fibre, 3.3 decitex blended with 30% polypropylene fibre, 2.5 decitex with a weight after thermal activation of 250 gsm and a gauge of 1.6 mm.